The LOOPING VCADSR is a 4-stage envelope generator that uses a Microcontroller from Electric Druid to generate a Voltage Controllable, Loop-able Envelope. The individual parts of the Envelope (Attack, Decay, Sustain, Release and Level) can all be individually controlled via CV.

This module has 3 MODES of operation:

• Normal Envelope – Gate signal fires ADSR
• Gated Looping Envelope – ADSR loops whilst gate signal is high.
• Looping Envelope – ADSR loops regardless of gate signal.

When the envelope is looping, all 5 controls affect the output. Attack and Decay operate, as one would expect. The Sustain control sets the minimum voltage the decay part of the envelope will decay to. The Release sets a release time from the end of the Sustain period to the beginning of the next cycle. When the Sustain is set to 0 you can use the Release control to add a delay between the Attack and Decay cycles.

In Normal Envelope mode the Sustain CV input can be used with an LFO source to add amplitude modulation that gradually increases as the Envelope transitions from the Attack/Decay part of the envelope into the Sustain part. The Level CV is also a useful point for amplitude modulation or can be used for Velocity Sensitivity via CV.

The Looping VC-ADSR is based on the ENVGEN 8C project by Electric Druid. You can read about the microcontroller that the design is based upon here. ENVGEN 8C